Vim's Buffers, Windows, and Tabs

by Noah Frederick | | level: beginner

Tabs are a popular UI paradigm for GUI text editors, browsers, and more. The fact that Vim also has a feature called “tab pages” that looks a lot like tabs from other programs can be a common source of frustration for newcomers. In a typical GUI editor, each tab represents a single document. Vim’s tab pages are not tied to documents at all, but rather contain window layouts. First, some definitions:

In Vim's parlance a buffer is an in-memory representation of a document, which may or may not correspond to a file on disk. A single buffer can be visible in more than one window at a time, or none at all.
A window is a viewport for displaying a buffer. There is always at least one window visible at all times. When you create a new "split" you are creating a window.
Tab Page
A tab page is a collection of one or more windows. There is always at least one tab page in existence. (Depending on your 'showtab' setting you may only see a listing of tabs when you have more than one.)

A Vim session with a couple of tab pages is shown below:

Diagram showing two tab pages containing different window arrangements and showing which buffers are visible in which windows
An illustration of the relationships among Vim's tabs, windows, and buffers. Buffers 4 and 6 are considered hidden, since they are not visible in any window.

Notice that Buffer 5 is visible in two windows at once, which can be useful if you need to reference two sections of a long file simultaneously, while buffers 4 and 6 are not visible in any windows. The biggest conceptual hurdle to overcome is that buffers are not tied to any UI element; they can come and go from any window in any tab. (But to add to the confusion, certain commands that operate on buffers, such as :bdelete, can also affect your window layout.)

This system of buffers, windows, and tab pages provides a lot of flexibility in that you can create multiple window layouts, you can view different parts of a buffer at the same time, and juggling 200 buffers is about as manageable as just two.

Further Reading